Internal combustion engines rely upon an ample source of clean air for proper combustion therewithin of the oxygen in the air mixed with a supplied fuel. In this regard, an air induction housing is provided which is connected with the intake manifold of the engine, wherein the air induction housing has at least one air induction opening for the drawing-in of air, and further has a filter disposed thereinside such that the drawn-in air must pass therethrough and thereby be cleaned prior to exiting the air induction housing on its way to the intake manifold.
Problematically, a consequence of the combustion of the fuel-air mixture within the internal combustion engine is the generation of noise (i.e., unwanted sound). A component of this noise is intake noise which travels through the intake manifold, into the air induction housing, and then radiates out from the at least one air induction opening. The intake noise varies in amplitude across a wide frequency spectrum dependent upon the operational characteristics of the internal combustion engine, and to the extent that it is audible to passengers of the motor vehicle, it is undesirable.
As shown at FIG. 1, a solution to minimize the audibility of intake noise is to equip an air induction housing 10 with an externally disposed resonator 12 connected to the air induction housing by an externally disposed snorkel 14. The air induction housing 10 has upper and lower housing components 16, 18 which are sealed with respect to each other, and are also selectively separable for servicing a filter media (not shown) which is disposed thereinside. An induction duct 20 is connected to the induction housing and defines an air induction opening 22 for providing a source of intake air to the air induction housing at one side of the filtration media, as for example by being interfaced with the lower housing component 18. An intake manifold duct 24 is adapted for connecting with the intake manifold of the internal combustion engine, and is disposed so as to direct the intake air at the other side of the filtration media out of the air induction housing 10, as for example via the upper housing component 16.
One end of the snorkel 14 is connected to the induction duct 20 adjacent the air intake opening 22. The other end of the snorkel 14 is connected to the resonator 12, which is essentially an enclosed chamber. Each end of the snorkel 14 is open so that intake noise may travel between the induction duct 20 and the resonator 12. The resonator 12 is shaped and the snorkel 14 configured (as for example as two snorkel tubes 14a, 14b) such that the intake noise passing through the induction duct toward the air intake opening in part passes into the resonator and then back into the induction duct so as to attenuate the intake noise by frequency interference such that the audibility of the intake noise exiting the air intake opening is minimized.
While the prior art solution to provide attenuation of intake noise does work, it does so by requiring the inclusion of an externally disposed snorkel and resonator combination which adds expense, installation complexity and packaging volume accommodation.
Accordingly, what is needed is to somehow provide attenuation of intake noise as an inherent feature of the air induction housing so as to thereby minimize expense, complexity and packaging volume.